File management method and system

ABSTRACT

The invention provides a file management method and system for managing file retrieval and access. The method operates at the operating system level within a file system of a computer device and allows creating file move links upon detection of a file move request. The file move link associates the file source location with the file target location and is stored within a file move link table of the file system for subsequent file access request. File path to target location is automatically retrieved and file reached transparently for the user.

TECHNICAL FIELD

The present invention relates to a file management method and system andmore particularly to a file move tracking method and system.

RELATED ART

Creating, managing, retrieving, and protecting data is a criticalrequirement of every business today. The efficient management of data isan ongoing struggle between access and scalability. Providing access tofile-level data (e.g., files associated with individual documents,multimedia files, databases and other applications) becomes moredifficult as more users are provided access and more data is stored.Achieving the scalability needed to respond to data volume growth alsotypically results in higher hardware and software costs, and greatermanagement challenges.

At the individual level, people often have several thousand files storedon their computer. Computers generally include a file system to storeand organize computer files and data. Essentially, file systems organizethe files into a database for the storage, organization, manipulation,and retrieval by the computer's operating system.

File systems are used on data storage devices such as hard disks orCD-ROMs to maintain the physical location of the files. The file systemis created when the hard disk is initialized. It sets up the rootdirectory and subsequent directories beneath the root directory. Thefile system allows the user to create new files and folders, which areadded to different parts of a “file tree” on the hard disk. For example,a hard disk has separate folders for programs, documents, pictures,music, and movie files. Within these folders, there are likely otherfolders that further organize the files. All these folders (ordirectories) are organized by the computer's file system. There are alsoseveral folders used by the computer's operating system to store systemfiles, such as startup data and system preferences. Some of thesefolders are invisible to the user, but are recognized by the computer'sfile system. The DOS, Windows, OS/2, Macintosh, and UNIX-based operatingsystems all have file systems in which files are placed somewhere in ahierarchical structure. A file is placed in a directory (or folder) orsubdirectory at the desired place in the tree structure. Windowsoperating system computers use file systems called FAT32 or NTFS.Macintosh computers used the HFS or HFS+ file system.

Beyond this, the file systems provide access to data on a file server byacting as clients for a network protocol (e.g., NFS, SMB, or 9Pclients), or they may be virtual and exist only as an access method forvirtual data (e.g., procfs).

File systems specify conventions for naming files. These conventionsinclude the maximum number of characters in a name, which characters canbe used, and, in some systems, how long the file name suffix can be.

A file system also includes a format for specifying the path to a filethrough the structure of directories. This path is used to reference thefile when needed either in system script (e.g., shell or bat) ordirectly in a program code or as OLE links to include a document inanother. The path may be an absolute path or a relative path: Anabsolute path is a path that points to the same location on one filesystem regardless of the working directory or combined paths. It isusually written in reference to a root directory. A relative path is apath relative to the working directory of the user or application, sothe full absolute path may not need to be given.

Storing a reference to a file or directory by using its path and filename is not reliable, as the path may be lost when a user renames ormoves files or directories. Renaming or moving files or directories arenevertheless desired and required operations. If a user renames a file,the links to the file are broken. If a user renames a directory, thelinks to the file are broken as well as all files and subdirectories inthe directory tree.

When a file then is moved to another place, all explicit and implicitreferences to the file become invalid, such as every program using thefile or every document that refers to the file.

Some solutions exist to allow file move while maintaining availableexisting references. A first approach is to use an alias as illustratedbelow for different operating systems:

a) Use system variables to identify a root directory:

-   -   SET X=C:\Myfile\Data\Other\Nonsense

and then use edit % X %\stuff.dat

instead of edit C:\Myfile\Data\Other\Nonsense\stuff.dat

b) DOS command SUBST that defines an alias as a disk:

-   -   SUBST M: C:\Myfile\Data\Other\Nonsense

and then use edit M:stuff.dat

instead of edit C:\Myfile\Data\Other\Nonsense\stuff.dat

c) Linux command ‘In’:

-   -   In MyData/Myfile/Data/Other/Nonsense

and then use edit MyData/stuff.dat

instead of edit/Myfile/Data/Other/Nonsense/stuff.dat

d) System path: use class path or command path.

The alias approach requires updating the alias when the file is moved toanother place and thus requires the user to initially create the aliasbefore the very first file use.

The NTFS file system for Windows provides a distributed link trackingservice which automatically tracks links as they are moved. The linktracking service maintains its link to an object by using an objectidentifier (ID) uniquely identifying a file or directory on a volume. Anindex of all object IDs is stored on the volume. This service isavailable for shortcuts only and furthermore requires the operatingsystem to explicitly subscribe to the service before using it.

U.S. Pat. No. 6,351,741 discloses a method of locating a file linked toa document in a relocated document directory structure. The methodallows retrieving a reference to a linked file linked to a document. Thereference specifies an absolute pathname. The mechanism parses theabsolute pathname into a plurality of relative pathnames and appends afirst one of the relative pathnames to a current directory specificationfor the document to produce a new absolute pathname. Subsequent ones ofthe plurality of relative pathnames are appended to the currentdirectory specification until the new absolute pathname points to thelinked file. While this system allows retrieval of a file in a structurethat has been moved or duplicated, the solution is based on a searchalgorithm that runs several searches before succeeding. Moreover thissolution concerns only files that are inside a sub-directory that havebeen moved or duplicated.

Accordingly, there is a need for a global solution of file move trackingthat operates on a complete host file system and that does not requirerunning successive operations to reach a moved file.

SUMMARY OF THE INVENTION

The present invention relates to a file management method and system andmore particularly to a file move tracking method and system.

A first aspect of the invention provides a computer implemented filesystem method for managing file access. The method comprises: detectinga file move request for moving a file from a file source location to afile target location; creating a file move link for the file associatingthe file source location to the file target location; and storing thefile move link in a file move link storage structure of the computerfile system for a subsequent file access request.

According to a second aspect of the present invention, there is providedan apparatus for carrying out the method according to the first aspectof the invention.

According to a third aspect of the present invention, there is provideda computer program comprising instructions for carrying out the methodaccording to the first aspect of the invention when the computer programis executed on a computer.

According to a fourth aspect of the present invention, there is provideda computer readable medium having encoded thereon a computer programaccording to the third aspect of the invention.

Further advantages of the present invention will become clear to theskilled person upon examination of the drawings and detaileddescription. It is intended that any additional advantages beincorporated therein.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention will now be described by way ofexample with reference to the accompanying drawings in which likereferences denote similar elements.

FIG. 1 is a flow chart of an illustrative process used for creating afile move link in accordance with an embodiment of the presentinvention.

FIG. 2 depicts an illustrative computer system suitable for runningembodiments of the present invention.

FIG. 3 is a flow chart of an illustrative process used for a file accessin accordance with an embodiment of the present invention.

FIG. 4 is a flow chart of an illustrative process used for a file or adirectory removal in accordance with an embodiment of the presentinvention.

FIGS. 5 a and 5 b depict an illustrative directory and a file move linkstructure in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

With reference to FIG. 1, a flow chart of a process 100 used forcreating a file move link is depicted in accordance with an embodimentof the present invention. The process begins by automatically detectinga file move operation (102). The file move operation requests to move afile from a source location to a target location. Next, a file move link(FML) is created between the source file location and the target filelocation (104). The file move link is stored (106) in a file move linkstorage structure of a file management system, and the process ends(108). In one embodiment, the file move link is stored in a relationaldatabase. However, a person skilled in the art would easily devise anyother variant of implementation for such a storage structure, such as,for example, having a dedicated local table at each level of the filedirectory, each dedicated local table storing the file move linksrelated to the files located within the respective directory.

While process 100 is described for a file move operation, the processapplies similarly when a directory move operation is detected as well.When a directory move operation is detected, a file move link is createdbetween the directory source location and the directory target location.

It is to be appreciated that a file move operation may also consider acut and paste operation of files as well as a file renaming operation.

The present invention provides a method, system and computer programthat operates at the operating system level within the file managementsystem for allowing a user to access transparently any file even if thefile has moved one or several times from an initial source location totarget location. The present invention allows keeping traceability offile move operations inside the file management system.

FIG. 2 shows a computer system 200 for supporting the file move trackingmethod of the present invention. The computer system 200 comprises aprocessor 210, a main memory 220, a mass storage interface 230, adisplay interface 240, and a network interface 250. These systemcomponents are interconnected through the use of a system bus 201. Massstorage interface 230 is used to connect mass storage devices (e.g.,hard disk drive (HDD) 255) to computer system 200. One specific type ofremovable storage interface drive 262 is a floppy disk drive which maystore data to and read data from a floppy disk 295, but may other typesof computer readable storage medium may be envisaged, such as readableand optionally writable CD ROM drives. There is similarly provided auser input interface 244 which receives user interactions from interfacedevices such as a mouse 265 and a keyboard 264. There is still furtherprovided a printer interface 246 which may send and optionally receivesignals to and from a printer 266. Main memory 220 in accordance withembodiments contains data 222 and an operating system 224. While notrepresented in FIG. 2, a file system is part of the main memory 220. Itis noted that the invention operates at the operating system levelwithin the file system.

Computer system 200 utilizes well known virtual addressing mechanismsthat allow the programs of computer system 200 to behave as if they onlyhave access to a large, single storage entity instead of access tomultiple, smaller storage entities such as main memory 202 and HDD 255.Therefore, while data 222 and operating system 224 are shown to residein main memory 220, those skilled in the art will recognize that theseitems are not necessarily all completely contained in main memory 220 atthe same time. It should also be noted that the term “memory” is usedherein to generically refer to the entire virtual memory of computersystem 200.

Data 222 represents any data that serves as input to or output from anyprogram in computer system 200. Operating system 224 is a multitaskingoperating system known in the industry as OS/400; however, those skilledin the art will appreciate that the spirit and scope of the presentinvention is not limited to any one operating system.

Processor 210 may be constructed from one or more microprocessors and/orintegrated circuits. Processor 210 executes program instructions storedin main memory 220 by operating on input data and generating output.Main memory 220 stores programs and data that processor 210 may access.When computer system 200 starts up, processor 210 initially executes theprogram instructions that make up operating system 224. Operating system224 is a sophisticated program that manages the resources of computersystem 200. Some of these resources are processor 210, main memory 220,mass storage interface 230, display interface 240, network interface250, and system bus 201.

Although computer system 200 is shown to contain only a single processorand a single system bus, those skilled in the art will appreciate thatthe present invention may be practiced using a computer system that hasmultiple processors and/or multiple buses. In addition, the interfacesthat are used in embodiments each include separate, fully programmedmicroprocessors that are used to off-load compute-intensive processingfrom processor 210. However, those skilled in the art will appreciatethat the present invention applies equally to computer systems thatsimply use I/O adapters to perform similar functions.

Display interface 240 is used to directly connect one or more displays260 to computer system 200. The displays 260, which may benon-intelligent (i.e., dumb) terminals or fully programmableworkstations, are used to allow system administrators and users tocommunicate with computer system 200. Note, however, that while displayinterface 240 is provided to support communication with one or moredisplays 260, computer system 200 does not necessarily require a display260, because all needed interaction with users and other processes mayoccur via network interface 250.

Network interface 250 is used to connect other computer systems and/orworkstations to computer system 200 across a network 270. The presentinvention applies equally no matter how computer system 200 may beconnected to other computer systems and/or workstations, regardless ofwhether the network 270 connection is made using present-day analogueand/or digital techniques or via some networking mechanism of thefuture. In addition, many different network protocols can be used toimplement a network. These protocols are specialized computer programsthat allow computers to communicate across network 270. TCP/IP(Transmission Control Protocol/Internet Protocol) is an example of asuitable network protocol, for example over an Ethernet network. Asshown, the network 270 connects the system 200 to two further devices271 and 272, which may be other computer systems similar to thatdescribed above, or other network capable devices such as printers,routers etc. In the present example, network device 272 is a Icl server,which is connected via a modem 281 to a public network 280 such as theword wide web. By means of this public network 280 a connection to aremote device or system 285 may be established.

FIG. 3 shows a process 300 used for processing file access in accordancewith an embodiment of the present invention. Process 300 begins when a“file not found” exception is detected by the file system (302). Fileaccess here may be interpreted as any operation intended to reach a filesuch as an edit, a move or a copy operation.

When a file is not reachable at the requested file path (302), theprocess enters a loop routine to search for the new file location of thefile, if any. A test variable (Suffix) is initialized and set to an‘empty’ value (304). A test is then performed to check if the file pathof the requested file path is empty or not (306). If the file path forthe requested file is found to be empty (branch Yes, 306), meaning thatno file exist at the requested path, the loops ends (308).

If the file path is found not to be empty (branch No, 306), the processenters a search operation of file move links (FML) in the file move linktable(s) (310). A test is then performed to check if a file move linkassociated with the requested file path is found or not (312).

If a file move link is found (branch Yes, 312), the process continues(316), as described further below.

If no file move link is found (branch No, 312), a new path is computedand the test variable (Suffix) is set to a new value (314). The new pathis defined as the parent path:F=getParent(F)and the value of the test variable is set as:Suffix=concatenate(getName(F)+Suffix).

Next, the process loops back, repeating (306) to (314) until a file movelink is found (branch Yes, 312).

When a file move link is found (branch Yes, 312), the process continuesand the new path is defined (316) as:NF=concatenate(NF,Suffix)

A test is then performed to check if the new path previously definedexists (318).

If the new path does not exists (branch No, 318), the new path isdefined for the requested file (320), and the process loops back to(304).

If the new path exists (branch Yes, 318), the requested file is provided(322).

With reference to FIG. 4, a flow chart of a process 400 used for file ordirectory removal is depicted in accordance with an embodiment of thepresent invention. The process begins by detecting a file removaloperation (402) initiated by a client application. Next, a search isperformed within the file move link storage structure (404) to searchfor existing links related to the file to be removed. If no file movelink is found, the process ends (410). Otherwise, for each file movelink found, the link is deleted and the process enters a loop to searchand delete the chain of links.

While process 400 is described for a file removal operation, the processapplies similarly for a directory removal operation.

FIGS. 5 a and 5 b illustrate schematically directories and file movelink tables in accordance with embodiments of the present invention.

FIG. 5 a exemplifies a file access when the file has been moved. Numeralreferences used in FIG. 5 a are identical to references used in FIG. 1and FIG. 3. At 102, the file located at source location D1/D11/F1 ismoved to target location D1/D14/D141/F3. At 104 and 106, a file movelink is created, namely [D1/D11/F1→D1/D14/D141/F3] link and stored inthe file move link storage structure. On a further attempt to access thefile F1 at its old location D1/D11/F1 at 300, the file management systemdoes not locate the file at 302, and a search is performed within thefile move link storage structure to identify the new location (304 to318). The file is accessed at its new location D1/D14/D141/F3transparently for the requesting application at 322.

An advantage of the present invention is that the original file path iskept as is to identify the file. This allows keeping standard ways toreference a file, and moreover to deploy the present method for filesthat are already referenced on a computer system before it isimplemented.

FIG. 5 b exemplifies a file access when a complete directory has beenmoved. Numeral references used in FIG. 5 b are identical to referencesused for steps of FIG. 1 and FIG. 3. At 102, directory located at D1/D11is moved to target directory location D1/D14/D141/D11. At 104 and 106, afile move link is created, namely [D1/D11→D1/D14/D141/D11] link andstored in the file move link storage structure. It is important to notethat only one file move link is stored for the root of the directory.

On a further attempt to access a file contained in source directorylocation (300), D1/D11/F1 for example, the file management systemgenerates an access failure. A search is then performed within the filemove link storage structure.

As the path D1/D11/F1 is not found in the table, a search on fileancestors D1/D11 is started (314). The new location is found (rootdirectory D1/D11) and the file move link previously created and storedallows providing access to the file at its new locationD1/D14/D141/D11/F1.

It is important to note here that the process for identifying the newlocation of a file is performed in two steps by searching in the fileancestry the first directory associated with a file move link, and thenby substituting the new directory path for the old one in the file path.

Finally, it is to be appreciated that the invention can take the form ofan entirely hardware embodiment, an entirely software embodiment or anembodiment containing both hardware and software elements. In apreferred embodiment, the invention is implemented in software, whichincludes but is not limited to firmware, resident software, microcode,etc.

Furthermore, the invention can take the form of a computer programproduct accessible from a computer-usable or computer-readable mediumproviding program code for use by or in connection with a computer orany instruction execution system. For the purposes of this description,a computer-usable or computer readable medium can be any apparatus thatcan contain, store, communicate, propagate, or transport the program foruse by or in connection with the instruction execution system,apparatus, or device.

The medium can be an electronic, magnetic, optical, electromagnetic,infrared, or semiconductor system (or apparatus or device) or apropagation medium. Examples of a computer-readable medium include asemiconductor or solid state memory, magnetic tape, a removable computerdiskette, a random access memory (RAM), a read-only memory (ROM), arigid magnetic disk and an optical disk. Current examples of opticaldisks include compact disk-read only memory (CD-ROM), compactdisk-read/write (CD-R/W) and DVD.

A data processing system suitable for storing and/or executing programcode will include at least one processor coupled directly or indirectlyto memory elements through a system bus. The memory elements can includelocal memory employed during actual execution of the program code, bulkstorage, and cache memories which provide temporary storage of at leastsome program code in order to reduce the number of times code must beretrieved from bulk storage during execution.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, etc.) can be coupled to the system eitherdirectly or through intervening I/O controllers.

Network adapters may also be coupled to the system to enable the dataprocessing system to become coupled to other data processing systems orremote printers or storage devices through intervening private or publicnetworks. Modems, cable modem and Ethernet cards are just a few of thecurrently available types of network adapters.

To summarize one of the advantages of the present invention, is to offera simple and efficient solution to avoid broken links (script orapplication failure) when files or directories have been moved.

The invention claimed is:
 1. A computer implemented file system methodfor managing file access, the method comprising: detecting a file moverequest for moving a file, wherein the file is identified by a filenameand a file source location, from the file source location to a filetarget location, wherein the filename does not change; creating a filemove link for the file associating the file source location with thefile target location; storing the file move link within a file move linkstorage structure of the computer file system for a subsequent fileaccess request; detecting a file access request searching for a filemove link associated with the file and the file source location;retrieving the file target location associated with the file move linkif a file move link is found; and providing access to the file at thefile target location; and after the searching: defining a new file pathfor the file if a file move link is not found, the new path beingdefined by concatenating a parent file path of the file; and repeatingthe searching for the new file path.
 2. The method of claim 1, whereinthe file move link creates an association between the file pathname ofthe source location and the file pathname of the target location.
 3. Themethod of claim 1, wherein the file move link is stored within a tableof the computer file system as a pointer between a file source pathnameand a file target pathname.
 4. The method of claim 1, wherein the filemove request or the file access request is received from a clientapplication running on the computer.
 5. The method of claim 1, whereinthe file move request is a request for moving a directory of files. 6.An apparatus for managing file access, comprising: at least one computerdevice for performing the following: detecting a file move request formoving a file, wherein the file is identified by a filename and a filesource location, from the file source location to a file targetlocation, wherein the filename does not change; creating a file movelink for the file associating the file source location with the filetarget location; storing the file move link within a file move linkstorage structure of the computer file system for a subsequent fileaccess request; detecting a file access request searching for a filemove link associated with the file and the file source location;retrieving the file target location associated with the file move linkif a file move link is found; and providing access to the file at thefile target location; and after the searching: defining a new file pathfor the file if a file move link is not found, the new path beingdefined by concatenating a parent file path of the file; and repeatingthe searching for the new file path.
 7. The apparatus of claim 6,wherein the file move link creates an association between the filepathname of the source location and the file pathname of the targetlocation.
 8. The apparatus of claim 6, wherein the file move link isstored within a table of the computer file system as a pointer between afile source pathname and a file target pathname.
 9. The apparatus ofclaim 6, wherein the file move request or the file access request isreceived from a client application running on the computer.
 10. Theapparatus of claim 6, wherein the file move request is a request formoving a directory of files.
 11. A non-transitory computer readablemedium having encoded thereon a computer program, which when executed bya computer device, performs a method for managing file access, themethod comprising: detecting a file move request for moving a file,wherein the file is identified by a filename and a file source location,from the file source location to a file target location, wherein thefilename does not change; creating a file move link for the fileassociating the file source location with the file target location;storing the file move link within a file move link storage structure ofthe computer file system for a subsequent file access request; detectinga file access request searching for a file move link associated with thefile and the file source location; retrieving the file target locationassociated with the file move link if a file move link is found; andproviding access to the file at the file target location; and after thesearching: defining a new file path for the file if a file move link isnot found, the new path being defined by concatenating a parent filepath of the file; and repeating the searching for the new file path. 12.The computer readable medium of claim 11, wherein the file move linkcreates an association between the file pathname of the source locationand the file pathname of the target location.
 13. The computer readablemedium of claim 11, wherein the file move link is stored within a tableof the computer file system as a pointer between a file source pathnameand a file target pathname.
 14. The computer readable medium of claim11, wherein the file move request or the file access request is receivedfrom a client application running on the computer.
 15. The apparatus ofclaim 11, wherein the file move request is a request for moving adirectory of files.